Multipolar magneto.



o. Hams. MULTIPOLAR MAGNETO.

APPLICATION FILED DEC.24. I915.

1,256,795. I Patented Feb.19,1918,

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' [MENTOR A TTORNEYS UNITED STATES PATENT OFFICE.

OTTO HEINS, OF NEW YORK, N. Y., ASSIGNOR T0 BOSCH MAGNETO COMPANY, OF NEW YORK, N. Y., A CORPORATION OF YORK.

MULTIPOLAR MAGINETO.

Specification of Letters Patent.

Patented Feb. 19, 1918.

Application filed December 24, 1915. Serial No. 68,505.

To all whom it may concern.

Be it known that I, OTTO Hams, a subject of the Emperor of Germany, residing at and whose ost'oifice address is 336 West 38th street, Lew York city, have invented certain new and useful Improvements in Multipolar Magnetos; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

It was customary heretofore to use bipolar magnetos for igniting the combustible mixtures in internal combustion engines, and this arrangement was satisfactory for the usual fourcyclc engines operating at ordinary speed, because the magneto and the gearing therefor operated well at crank shaft speed for four cylinders, and one and one half times crank shaft speed for six cylinders. However, for eight or twelve cylinder engines requiring a speed for a bipolar magneto of two or three times crank shaft speed, and also for high speed engines with four or six-cylinders operating at 2500 to 3500 R. P. M., the operation of the gearing is not entirely satisfactory, and the magneto is more likely to miss on account of centrifugal force acting on the interrupter elements.

My invention is directed to a multipolar magneto, that is one in which the armature and field have four or more poles each, and the object of the invention is to provide a magneto of small size capable of being at- ,tached to an engine for actuation thereby at comparatively low speed, the arrangement being such that any number of poles may be provided without departing from the general design. Such a magneto may be driven directly by the crank shaft of the engine, thus eliminating magneto gearing, and distributing mechanism for distributing the sparking voltages generated in the secondary winding may be carried by the rotatable member of the magneto and thereby eliminate the distributer gearing also.

In my improved form of magneto, the armature is provided with a plurality of wound poles projecting outwardly from the supporting core, either radially or axially,

and the field is made up of a continuous series of alternately-reversed permanent magnets of U-form forming a ring, either around the armature or at the side thereof, with the arms extending inwardly in both cases into cooperation with armature poles. Either the armature or the field may be rotated to generate periodically reversing voltage in the primary winding and a mechanical interrupter is connected to the winding to alter the circuit thereof at appropriate intervals. Preferably, the armature poles are wound with secondary windings also, so that high tension voltage suitable for producing sparks at spark gaps of jump-spark plugs may be generated in the magneto.

In the accompanying drawings illustrating the preferred construction in application to a six pole magneto for a twelve-cylinder four-cycle engine, wherein, as an example, the armature is rotatable and distributer brushes are carried thereby,

Figure 1 is a longitudinal section of the magneto on line l-1 of Fig. 2;

Fig. 2 is a vertical section on line 2-2 of Fig. 1;

Fig. 3 is an end elevation with the cover of the mechanical interrupter removed; and

Fig. 4 is a wiring diagram.

The armature is fast on a rotatable shaft 1 and is made up of iron laminations bolted together and forming a central core 2 and six radially-disposed outwardly-projecting poles 3. A primary coil 4 and a secondary coil 5 are mounted on each pole.

The field member is stationary and is composed of six. permanent magnets of U- form, forming a. ring or a continuous'series be stronger magnetically than. they wouldotherwise be, they are shaped for increased length by bending them in wide curves at the extremity of the arches 6 and convergirigg'the arms 7 and 7 in directions substam tialliyiradially-inward; and in order to reduce-the tendency of the magnetic flux to passarourld the field member without entering the armature, the magnets are separated throughout their length and the rear faces of the pole shoes 8 and 8 are recessed betweenfthe' arms of adjacent magnets. In this way',-' a multipolar permanent magnet field of much strength is obtained in a small spacepwhile the leakage and diversion of the flux from'l the armature is reduced.

The side plates 9 of non-magnetic material abut-the side faces of all the magnets and are tl'amped thereto by cross bolts 10. A screw 11 passes through the arch of each magnet an is threaded into an anchor block 1'2 through which a cross bolt 10 passes. Thus the magnets may be adjusted radiallyindependently of each other by the screws 11, so as t properly adjust the air gap, and afterward {the magnets are fixed rigidly with respect to the side plates in adjusted position by tightening the nuts on the cross bolts. The field member is held in position with respect tothearmature through the bearings 12 of the shaft, and the magneto is provided with a base or stand 13 depending from the ipide plates and with a non;magneti'c strap 14 encirc ing the magnets. The

, magneto shown in the drawings is about 7 The magneto shown is j 06' mchjes in diameter.

'The mechanical interrupter for periodicall'y interrupting the circuit of the primary winding 4 comprises the grounded interr'upter element 15 and the insulated element 15; mounted for rotation with the armature, and the six equally spaced interrupter cams 16 carried by a normally stationary cam ring 17 provided in the well known way with means (not shown) for adjusting at will its circumferential position to advance or retard the period of ignition. The six primary coils 4 are connected in series, one terminal being connected to the interrupter element 15 and the other terminal being rounded. A coil condenser 18 is mounted Iast on the'shaft 1, and is connected between the insulated interrupter element and the ground.

The six secondary coils 5 are connected in series and the two insulated terminals are connected respectively to the two springpressed distributer brushes 19 and 19, which are carried by the armature for rotation. therewith. ere is a series of spa rkplug distributing contacts 20 and 20 at each end of the armature coiiperating with the individual brushes 19 and 19. These contacts are embedded in plates 21 of insulating material fixed in position to the side plates 9. Each contact is connected to an individ ual binding post 22. a

intended to be driven directly by the crank shaft of a twelve cylinder engine, and the twelve binding posts electrically connected to the insulated electrodes of spark plugs in the individual cylinders, as shown in Fig. r.

As in ordinary bipolar magnetos for ignition systems, anignition voltage is gcnen ated substantially in the period in which the armature poles bridge the spaces bctween adjacent field poles, the circuit of the primary winding being opened, by the mcchanica-l interrupter at the moment of ignition as a result of deflecting interrupter lever 15 and a cam 14;. In eachrotation of the nmgncto herein shown, this occurs six times, and accordingly six ignition voltages are generated in the secondary winding. During each prriod of ignition, the distributing brushes ll! and 19 engage two spark-plug distributing contacts 20 and :20, and the sparks occur simultaneously at the two spark plugs rouncctcd in series with the secondary windihg at that time, the arrangement being sin-h that the piston of one of the cylinders in which a spark occurs is in the explosion stroke while the piston of the other rylinder is in its exhaust stroke.

II. will be apparent from the foregoing that a magneto of the same general design may lie-provided with 4, 8, 12 or other suitable number of poles, and if desired, the magneto may be driven by the engine through speed change gearing, the number of poles being properly selected to furnish ignition voltagcs at appropriate periods. It will also be apparent that, if desired, the type of magneto herein disclosed may be associated with distributing mechanism of the ordinary kind driven from the magneto through two to one speed reducing gearing for four-cycle engines. a

What I claim is:

1. In a multipolar magneto for electrical ignition systems, a ring lield member composcd of a continuous series of alternatelyrevcrsed permanent magnetsof U- form with their arms extending inwardly to common polesof alternating polarity throughout the series, an armature member having a generating winding and a plurality of outu'urdlvprojecting poles constructed and arranged to bridge the spaces between the liuld poles, and a mechanical interrupter electrically connected to the generating windiir our of said members being rotatable.

2. In a multipolar magnet for electrical ignition systems, a ring field member composed of a continuous series of reversed permanent magnets of U-t'orm with their arches extending in circular alincmrnl.

and with their arms extending inwardly having a. generating winding and a plurality of engagement between the.

altornal Pl)".

polarity I radially-disposed poles constructed and arranged to bridge the spaces between the field poles, and a mechanical interrupter electrically connected to the generating winding, one of said members being rotatable.

3. In a multipolar magneto for electrical ignition systems, a. stationary ring field member composed of a continuous series of alternately-reversed permanent magnets of U-form with their arms extending to common poles of alternating polarity throughout the'series, a rotatab e armature having a generating winding and a plurality of poles constructed and arranged to bridge the spaces between the fieldpoles, and a mechanical interrupter electrically connected to the generating winding.

1. In a multipolar magneto for electrical ignition systems, a field member comprising a plurality of pole shoes of alternat ng polarity and a continuous series of alternatelyreversed permanent magnets of U-form magnetically connected to the pole shoes, an armature member embraced by the field member and having a generating winding and a plurality of radially-disposed poles constructed and arranged to bridge the spaces between the field poles, and a mechanical interrupter electrically connected to the generating winding, one of said members being rota-table.

5. In a multipolar magneto forelectrical ignition systems, an armature member having a generatin winding and a plurality of poles, a ring eld member composed of a continuous series of alternately-reversed permanent magnets of U-form shaped for increased length, common pole shoes magnetically connecting the arms of like polarity of,adjacent magnets and forming a series cooperative with the armature poles and of alternating polarity throughout, and a mechanical interrupter electrically connected to the generating Winding.

6. In a multipolar magneto for electrical -1gnit1on systems, an armature having a generating winding and a plurality of poles, a ring field composed of a continuous series of alternately-reversed permanent magnets of U-form separated from ,each other throughout their length, common pole shoes magnetically connecting the arms of like polarity of adjacent magnets and forming a series of poles of-alternating polarity cooperative with the armature oles, and a mechanical interrupter electrically connected to the generating winding.

7. In a multipolar magneto for electrical ignition systems, an armature having a generating winding, a field composed of perma nent magnets separated from each. other throughouttheir length, common pole shoes magnetically connecting like poles of adjacent magnets and forming a series ofp'oles of alternating polarity cooperative with the ignition systems, an armature having a gen crating winding, a field composed of a series of alternately-reversed permanent magnets of U-form shaped for increased length and separated from each other throughout their length, common pole shoes magnetically connecting like poles of adjacent magnets .and forming a series of poles of alternating polarity coiiperative with the arma' ture poles, and a mechanical interrupter electrically connected to the generating winding, the rear faces of said pole shoes being recessed between the arms of adjacent magnets for the purpose described.

9. In a multipolar magneto for electrical ignition systems, a multipolar armature having poles, a multipolar field composed of permanent magnets, a mechanical interrupter having interrupter elements and coiiperative interrupter cams, a primary winding composed of coils mounted on the armature poles and connected in series with each other and with the interrupter elements, and a secondary winding composed of coils also mounted on the poles and connected in series with each other.

10. In a multipolar magneto for electrical ignition systems, a rotatable armature having a plurality of radially-disposed poles, a lowtension winding on said poles, a stationary ring field composed of a continuous series of alternately-reversed permanent magnets of U-form shaped for increased length and separated from each other throughout theirlength, said magnets having their arches extending in circular alinementaround the armature and having their arms extending inward, common pole shoes magnetically-connecting the-arms of like polarity of adjacent magnets and forming a series of poles of alternating polarity cooperative with the armature .poles, and a mechanical interrupter having interrupter elements carried by the armature and elec-.

trically connected to the terminals of said winding and also having interrupter cams coiiperative with the interrupter elements to alter the circuit of the winding at'appropriate periods.

11. In a multipolar magneto for electrical ignition systems, an armature member having a generating winding, a ring field member embracing the armature and comprising a plurality of permanent magnets, a mechanical interrupter electrically connected to the generating winding, bearings, one of said members being rotatable in said bearings, and fastening means rigidly fastening the permanent magnets to the bearings.

erating winding and radially-disposed poles a ring field member embracing the ar Tature alnl comprising a plurality of radially-adl jnstalihpermanent magnets, a mechanical interrupter electrically connected to the generating ninding, side plates fixed in relation to the axis of rotation of the magneto, and fastening means permitting radial adjustment of the magnets and clamping the magand clamping the side nets between the side tion.

14. In a I'nultipolar magneto for electrical ignition systems, a rotatable armature having a generating winding and radially-disposed poles, a ring field member embracing the armature and comprising a plurality of permanent magnets of U-form, a mechanical interrupter electrically connected to the gen-- crating winding, stationary side plates, and fastening means comprising for each magnet an anchor block inside the arch of the magnet and connected thereto in radially-ad justable position by a screw, and also comprising atie rod engaging the anchor block plates in radially-atljnsted position against the opposite side faces of the magnets.

In testimony whereof I 'alfix my si natm'e,

. OTTO H IN plates in -adj usted posi- 

